Teigen, 31 — who is expecting her second child with John Legend, 38 — is experiencing something that women often face during gestation, pregnancy headaches.

“This is actually really common,” Dr. Monica Svets, an obstetrician and gynecologist at Cleveland Clinic, told TODAY. “It is definitely a response to the overwhelming hormone changes from being non-pregnant to pregnant."

Headaches ease as pregnancy progresses

The body experiences a surge of progesterone and estrogen to “support the pregnancy,” but this leads to all sorts of icky symptoms, including nausea and vomiting. Like morning sickness, headaches normally become less common as the pregnancy continues.

“It is overwhelming in the first trimester,” Svets said. "They tend to settle down."

Headaches might feel more severe during pregnancy because women have fewer options to treat them.

“She sounds like she is pretty miserable,” said Dr. Christine Greves, an obstetrician and gynecologist at Orlando Health. “It does seem worse probably in pregnancy because you are limited in the ability to make it better.”

Pregnant women cannot use nonsteroidal anti-inflammatory drugs or NSAIDS, such as ibuprofen or naproxen. And, many of the things Teigen shuns, magnesium, water, and Tylenol, generically known as acetaminophen, represent the only headache treatment options for pregnant women. (No word on whether witchcraft is effective). Even still some women feel wary about using acetaminophen while pregnant.

“Some women are purists and try to avoid any medication for pain,” Svets said.

Chrissy Teigen/Snapchat

Morning sickness and lack of sleep can contribute to increased headaches, so experts recommend women remain hydrated, supplementing with sports drinks if needed, and sleep through the night or take naps. Svets sometimes recommends that her patients try alternative therapies, such as acupuncture and massage.

Sometimes headaches can be a sign of a serious problem. If women experience pain that feel like “the worst headache” of their lives or have neurological symptoms, such as numbness, tingling, or loss of some vision, they should see their doctors. This could be a sign of a mass in the brain, blood clots, or a stroke. While it is important to rule out such conditions, they are not usually the reason behind headaches.

While first semester headaches are normal, pregnant women should be more mindful of headaches later in pregnancy. Headaches can be a sign of preeclampsia, a sometimes fatal condition occurring after 20 weeks of pregnancy. Symptoms include high blood pressure, headaches, protein in urine, blurred vision, nausea, vomiting, and pain in the upper right abdomen.

“The preeclampsia type of a headache can be on both sides of the head and it seems like it gets worse and worse. And there's kind of a pulsating feeling,” Greves said. "It may not respond to over-the-counter medication."

For most pregnant women, “there is not really a whole lot of harm that a headache is going to cause,” but she urges them to talk to their doctors if they have them.

“Don’t feel bad for discussing a problem with your doctor,” she said. “That is what we are here for.”